Progress: controller program, implementing failsafe.

Progress: controller program, implementing failsafe.

Minor code cleanup:
- Removing no longer valid documentation.
- Cleaning up syntax, such as spacing.
- Updating documentation comments.
- Pass controller_main_t as a pointer in the entry function, updating all uses.
- Remove @fixme for considering status handling because I don't plan on bothering with this now.

A lot of the controller_print_unlock_flush() calls are using the incorrect stream.

Use status_lock as a return in cases where the status that is retuned shouldn't become lost when processing the locks.
Otherwise, the errors may never properly bubble to the parent and therefore may never trigger the failsafe.

The failsafe is not a rule id, but instead an item id.

If and when failsafe support is enabled, trigger it.
The currently implemented code only handles synchronous failures.

Begin work with adding a "failed" flag so that asynchronous, but required, failures can be detected for the purposes of failsafe execution.